UnrealEngineUWP/Engine/Source/Runtime/InteractiveToolsFramework/Public/TargetInterfaces/MeshDescriptionProvider.h

// Copyright Epic Games, Inc. All Rights Reserved.

#pragma once

#include "CoreMinimal.h"
#include "UObject/Interface.h"
#include "TargetInterfaces/MeshTargetInterfaceTypes.h"
#include "MeshDescription.h"

#include "MeshDescriptionProvider.generated.h"

UINTERFACE()
class INTERACTIVETOOLSFRAMEWORK_API UMeshDescriptionProvider : public UInterface
{
	GENERATED_BODY()
};

class INTERACTIVETOOLSFRAMEWORK_API IMeshDescriptionProvider
{
	GENERATED_BODY()

public:
	/**
	 * Access the MeshDescription available through this Provider. Note that this MeshDescription may or may not 
	 * be owned by the provider and should not be modified directly. Use IMeshDescriptionCommitter for writes.
	 * @return pointer to MeshDescription 
	 */
	virtual const FMeshDescription* GetMeshDescription(const FGetMeshParameters& GetMeshParams = FGetMeshParameters()) = 0;

	/**
	 * Returns an empty mesh description appropriate for the provider, i.e. configured with appropriate mesh
	   attributes but otherwise devoid of topology or element data.

	   Note: Some of our code expects at least FStaticMeshAttributes to be registered with the provided
	   mesh description, and will break if some of the attributes that FStaticMeshAttributes uses are not present.
	   The only reason we don't provide a default implementation here that is identical to the one used in
	   StaticMeshToolTarget.cpp is to avoid a dependency on the static mesh description module in ITF.
	 */
	virtual FMeshDescription GetEmptyMeshDescription() = 0;

	/**
	 * Get a copy of the MeshDescription available through this Provider. 
	 */
	virtual FMeshDescription GetMeshDescriptionCopy(const FGetMeshParameters& GetMeshParams)
	{
		return *GetMeshDescription(GetMeshParams);
	}

};